Error in start app elixir/phoenix docker in container

Phoenix Forum Questions / Help
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1

When I perform my elixir / phoenix application locally.

mix phx.server

Start normally.

But when I put it in the container, it returns me
Instrumenter.Phoenix.init / 1 is undefined or private

My application has the distiller and I’m integrating the prometheus in Phoenix.

What could be happening?

2

:wave:

What could be happening?

One unlikely possibility is your container uses an environment different from dev (which is what you usually use with mix phx.server) for which Instrumenter.Phoenix wasn’t compiled.

3

When posting an error, please always include the full stack trace.

4

Stacktrace:

** (UndefinedFunctionError) function Test.Instrumenter.Phoenix.init/1 is undefined or private
    EudorosProducerWeb.Instrumenter.Phoenix.init([])
    (plug) lib/plug/builder.ex:302: Plug.Builder.init_module_plug/4
    (plug) lib/plug/builder.ex:286: anonymous fn/5 in Plug.Builder.compile/3
    (elixir) lib/enum.ex:1948: Enum."-reduce/3-lists^foldl/2-0-"/3
    (plug) lib/plug/builder.ex:284: Plug.Builder.compile/3
    (plug) expanding macro: Plug.Builder.__before_compile__/1
    lib/eudoros_producer_web/endpoint.ex:1: Test.Endpoint (module)
ERROR: Service 'web' failed to build: The command '/bin/sh -c mix deps.get --only prod &&     mix compile' returned a non-zero code: 1
5

Is there a ENV MIX_ENV=prod in the docker file before the failing line?

If not, then it will try to compile as dev but misses dependencies, as you only downloaded for prod before…